[unreadable] In response to PA-04-061 and PA-01-097, this revised proposal describes a health services research project to examine patterns of service use by adolescents with substance abuse problems living in rural areas using the R21 Exploratory/Developmental Grant mechanism (PA-02-171). The specific aims of this project are: 1) To generate new knowledge on rural adolescents' use of behavioral health services for substance use disorders by: a) Describing differences in predisposing, enabling and need characteristics between rural and non-rural youth entering publicly funded substance use treatment, with a focus on levels of substance use, mental health issues and physical health characteristics, and b) Testing hypotheses about differences between rural and urban populations in access and service use patterns and clinical outcomes; and 2) To refine established theoretical models of service use and outcomes for future health services research with this population. The project will use previously collected interview and administrative data. Secondary analysis is an efficient method for gaining insight into the experiences of youth struggling with substance abuse problems in rural settings. Descriptive and hypothesis-testing analyses are proposed around two areas: 1) what are the types of substances used, patterns of substance use, and consequences of substance use among rural youth entering publicly-funded substance abuse treatment? How do these differ from urban youth? 2) What are types of substance abuse services used, patterns of service use, and consequences (outcomes) of treatment for rural youth? How do these differ from urban youth? Descriptive analyses will focus unadjusted differences. The multivariate hypothesis-testing analyses will consider differences in service use and clinical outcomes between rural and urban youth, using multi-level modeling to assess the influence of community and service system variables. Relevance: As highlighted at the NIDA-sponsored Drug Abuse Research in Rural Communities: Current Knowledge and Future Directions meeting (12/2004) of experts in substance abuse and rural studies, improving understanding of substance abuse and its treatments in rural areas is a national imperative, and comparative studies are needed. This project provides a unique opportunity to address these critical issues by studying differences in rural and urban substance abuse patterns, barriers to treatment, service utilization and outcomes for youth. Given that Medicaid is the largest health insurance program in the country for adolescents and that at least one out of every five substance services are funded by Medicaid, examining these questions for Medicaid-enrolled youth strengthens the policy relevance of the findings. [unreadable] [unreadable]